1. Field of the Invention
The present invention relates to an motor-driven stapler comprising a table that is arranged as opposed to a staple drive portion for driving a staple and is provided vertically movable on the stapler body.
2. Description of the Prior Art
Conventionally known is a motor-driven stapler comprising a table arranged as opposed to a staple drive portion of the stapler body and provided vertically movably, a driver for driving staples from said staple drive portion, a cartridge in which sheet staples are accommodated in a stacked configuration, and a feed mechanism for feeding the sheet staples, accommodated in the cartridge in a stacked configuration, to the staple drive portion.
Such motor-driven stapler allows the driver to be downwardly positioned to cause said staple drive portion to drive the staples when said table has been moved upwardly to press sheets of paper against said staple drive portion. The tip portions of a staple driven penetrate the sheets of paper and are then clinched by a clincher that is provided on said table.
In such a motor-driven stapler, the table is adapted to move vertically in parallel and thus collides with the staple drive portion with the initial attitude thereof maintained. This caused a loud impact noise to occur.
Moreover, the impact or the like would cause the sensor means for sensing the home position of the table to malfunction.
In addition, the feed mechanism for feeding sheet staples to the staple drive portion is provided on the stapler body and the cartridge is attached to the stapler body detachably. Accordingly, the positional relation between the cartridge and the stapler body is critical to feed the sheet staples in the cartridge to the staple drive portion and requires both the cartridge and the stapler body for strict accuracy in dimensions.
A first object of the present invention is to provide a motor-driven stapler that can reduce impact noise.
A second object of the present invention is to provide a motor-driven stapler that can prevent the sensor means for sensing the home position from malfunctioning due to impacts.
Furthermore, a third object of the present invention is to provide a motor-driven stapler that requires the control of dimensional accuracy of only the cartridge.
According to a first aspect of the present invention, the motor-driven stapler is characterized by comprising a table arranged as opposed to a staple drive portion for driving a staple and provided movably up and down on a stapler body, and a driver for driving staples from said staple drive portion to sheets of paper when the table has been moved to press the sheets of paper against said staple drive portion, wherein
the table is pivotally carried on the stapler body about axles to move up and down.
According to a second aspect of the present invention, the motor-driven stapler is characterized by comprising a table arranged as opposed to a staple drive portion for driving a staple and provided movably up and down on a stapler body, and a driver for driving a staple from said staple drive portion to sheets of paper when the table has been moved to press said sheets of paper against said staple drive portion,
said motor-driven stapler being provided with a position sensor mechanism for sensing a home position of said table, wherein
said position sensor mechanism comprises a position cam provided on a drive shaft for moving said table up and down, a one end of which is rotatably pivoted, and arm sensor means for sensing that said sensor arm has rotated to a predetermined position,
said position cam is provided, on a circumferential surface thereof, with a recessed portion for indicating said home position and a projected portion symmetrically opposite to the recessed portion, and
said sensor arm has a first arm portion where a first top end portion is slidingly in contact with the circumferential surface of said position cam, a second arm portion where a second top end portion is slidingly in contact with the circumferential surface of said position cam, wherein said first top end portion and said second top end portion sandwich said position cam, said first top end portion is slidingly in contact with said recessed portion, and said second top end portion is slidingly in contact with said projected portion and said sensor arm rotates to a predetermined position.
According to a third aspect of the present invention, the motor-driven stapler is characterized by comprising a table arranged as opposed to a staple drive portion for driving a staple and provided movably up and down on a stapler body, a driver for driving a staple from said staple drive portion to sheets of paper when said table has been moved to press said sheets of paper against said staple drive portion, and a cartridge for accommodating sheet staples, attached detachably to said stapler body, and provided with said staple drive portion, wherein
said cartridge is provided with a mechanism for feeding sheet staples accommodated in said cartridge to said staple drive portion.